Electric tool



C. B. BENNETT ELECTRIC TOOL Filed Nov. 5, 1921 v 2 Sheets-Sheet l N Nh.NQ. .E

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July 2z, 1924. 1

' C. B. BENNETT ELECTRIC 'TOOL Filed NOV. 5 192] 2 Sheets-Sheet 2 and ismounted on a removable head provide for 3o ism from the` switch inveniently closed for 5o ticularly pointed out` in the Patented July 22,1924- UNITED STATES PATENT OFFICE.

CHARLES B.. BENNETT, OF LOUISVILLE, KENTUCKY, ASSIGNOR TO JAMES CLARK,JB. ELECTRIC COMPANY, OF IUISV'ILLE, KENTUCKY, A CORPORATION OFKENTUCKY.

ELECTRIC Toor..

Application led November 5, 1921. Serial No. 513,037.

10 cludes electric motors, and an object'of the invention is to rovidesuch a tool with an improved hand e shaped and arranged to facilitatethe manipulation of the tool. The.

handle is of the type used on hand-saws, of the motor casing, wherebythe `handle is removed with the removable, head whenever access is tobe'had to thel motor.

A further'object of the .invention is to conveniently actuating theelectric switch for starting and stopping the operation of the motor,and also to enable the actuation of the switch by the operators handwhich holdsI or grasps the handle. j I

25 mount. the switch and all electrical connec- -tions on the motorcasing, while the switch actuating mechanism is mounted on S the han le,provision being made for convenient disconnection ofthe actuatingmechan- 4 order that the removal of the handle 4may not disturb theswitch nor'any of the electricalconnections. When. the tooll is not inoperation, the switch is ofcourse open and may be constarting the motormerely by pressing uponA the actuating lever mounted upon the handle. Onreleasin the lever, which is spring pressed), the switcl will be snappedinto its open position so as 4o to :sto thefmotor.D Provision is alsomade where y the switch may 'be Amaintained close; without re uiring theoperator to hold the actuating sit-ion.4v u

lWith these and other objects in'view, the

' present invention consists in the combination` and arrangement ofparts as will be hereinafter more fully described, illustrated in theaccompanying vdrawings and parappended a1ms, it `of course beingunderstood that changes in the form, proportion, size andI minorYdetails may be made, within the sco e of the claims, without departingfrom t e 'form but preferably in the form of an ings indicated in everin its retracted po 'housed within the casing spirit or/,sacricing anyof the advantages of the' invention.

In the drawings:

Figure 1 is a side elevation of an electric tool embodying the featuresof the present invention, theA handle and the switch casing being insection to expose the electric switch and the actuating lmechanismtherefor.

' Figure 2 is a side elevation, on an enlarged scale, of the switchremoved from the motor casing.

Figure 3 is a bottom plan view of the switch with the casing' insection.

Figure 4' is a side elevation looking at the opposite side of the toolfrom that shown in- Figure 1.

Figure 5 is an enlarged detailedperspective View of one of the switchelements.

Figure 6 is a detailed perspective view of the bell crank link or memberofthe toggle portion of the switch.

Figure 7 is a detailed perspective view of the spring actuated link ormember of the to e.

igure 8l is-.a detailed fragmentary view illustrating'the positions ofthe toggle mem.

tor lof the tool, not shown, is contained Y within a motor casing 1 ofany desired o en ended cylinder provided with a front premovable head 2and a rear removable head 3, each off said heads being detachably heldin place by suitable screw threaded fastenable tool spindle 5 projectslongitudinally at the front-of the casing and is equipped with asuitable chuck 6 to -which an appropriate form of drill or tool may hefitted in the usual manner. By reason of the fact that the heads 2 and 3may be removed, access may be' conveniently had to the motor In carryingout one of the features of the presentinvention, a handle is providedupon the rear removable head 3, this handle preferably being .of thetype commonly dotted lines at 4. A suit- 13 and the block 16.

employed upon hand-saws and includes a grip or cross-bar 7 connected atits top and bottom with the removable head 3 by means of the connectingelements 8 and 9. While not necessary, I prefer to form the head 3 andthe parts of the handle as an integral casting. With a handle of theform shown in the drawings, very convenient manipulation of the tool maybe had, as the entire tool lnay be held in one hand and pressure applieddirectly to the rear end of the tool in the most'eifective andsatisfactory manner.

While any desired form of electric switch may be. employed tor startingand stopping the motor, a satisfactory switch construction has beenshown in the drawings. This switch mechanism includes a base member 10fitted flat against the bottom of the motor casing and secured theretoby suitable astenings 11 extending through perorated ears 12 projectinglaterally from said base member. Extending along each edge of the basemember is a depending iiange 13 which extends beyond the rear of themember and is deiected downwardly to form an arm 14. The two arms 14constitute a fork or yoke at the rear end of the base member 10. Each ofthe flanges 13 is provided with an outwardly directed shoulder 15 formedby bending outwardly a portion of the iiange. A block of insulating'material 16 is disposed between the anges 13 and secured thereto bysuitable fastenings 17 extending through the flanges A contact member 18is suitably secured to each side 'of the block 16 and has a fingerportion 19 projecting rearwardly at the rear end of the block. suitablebinding post 2O is provided for each of the contacts.

Electric connection is established between the two finger-portions 19 ofthe two contact members 18 by a snap device in the form ot a toggleincluding a bell crank member 21 made up'ot a pair of duplicatesegmental plates 22 connected at their rear edges by a cross-bar orplate 23. This bell crank member is received between the arms vofthefork or yoke 14 to which it is pivoted as at 24 in Figures 1 and 2.Suitable stop projections 25 arise `tromv the top edges of the plates 22and overhang the top of the yoke arms 14 so as to contact therewith andlimit the pivotal movement of the bell crank member in one direction. Infront of the bell crank member is a link 26 made of insulating materialand slotted or bifurcated longitudinally to form yoke or fork arms 27which are received between'. the side members 22 of the belll crank.Each of the fork arms 27 is provided with a notch or seat 28 receiving apin or projection 29 extending inwardly rom the adjacent side wall 22 ofthe bell crank lever.- A helical spring`30 is disposed in the slot orbifurcation of the link 27 and has one end Aconnected toa pin 31extending through the bifurcated portion' of4 the link, vthe other endofthe spring being connected to the pivot pin 24. Normally the positionof the A lthe spring 30 is moved across the center,

whereupon the pins 29 will become the pivotal support for the rear endof the toggle link 26 and the latter will be snapped downwardly to theposition shown in dotted lines 'in Figures 1 -and 2` with its members inengagement-.with the contact fingers 19. thereby establishing anelectric connection between said finger-portions 19. permitting currentto flow from one of the elements 18 to the other element 18 through theconducting rollers 32 and their connecting pin or axle 32. This is the.closed position of the switch which starts the electric motor andmaintains it in operation.

The means for manually actuating the snap switch includes a lever 33mounted within the hollowA handle 7 and inserted therein through a slot34 in the inner tace of the handle. This lever is fulcrumed intermediate of its ends as at 35 and has its lower end connected to thelower end of the bell crank 21 by means of a connecting -rod 36 pivotedas at 37 to the bell crank and connected to the lower end of the lever33 by means of the removable pivot pin 38. The connection'38 ispreferably a screw threaded pin capable of being removed, forconvenience in connecting and disconnecting the link or rod 36 to thelever 33. Aceessto the removable fastening 38 is obtained through anopening 34 in the handle. The upper end of the lever 33 normally lies infront of the handle and is laterally enlarged to"form a lfinger pieceorl grip 39. A compression spring 40 is fitted within a seat 41 in thehandle 7 and bears against the rear side of the lever 33 adjacent theupper end of the finger piece portion thereot` so as to normally andyieldably maintain the lever in thel position shown in Figure with theswitch in its open position. open at its rear end and is provided with aclosure 42 in the form of a screw'plug whereby the spring may beconveniently tted inplace and removed.

The tool is provided with a cable 43 of suitable length and provided atits free end The seat 41 is Hill start the motor,

Amoana with a plug or suitable connector. This cable is secured to themotor casing by a suitable clamp or bracket 44. One of the conductors 45leads`from the cable to one of the'binding posts 20 while the otherconductor'46 4leads to a binding post 47 pro,- vided upon the bottom ofthe casing and connected inside of the casing to the motor in any wellknown or approved manner. A conductor 48 leads from the other bindingpost 20 upward] through the bottom of the casing and to t e motor in anyapproved manner.

With the parts in positions shown byfull lines in Figure 1 of thedrawings, it will be understood that the switch is open. To

the operator takes the liandle 7 in one hand and presses against the finger piece 3910i the switch actuating lever 33, whereby the lower end ofthe lever will be moved forwardly to the dotted position carryin with itthe link or connecting rod 36 whic will turn or rock the bell crank 21to the dotted osition which, ashereinbefore described, wil resultin thebreaking of the tog le, formed by the bell crank 21and the li 26,whereby vthe latter will be snapped down into engagement with thecontacts 19, thus closin the switch and starting the motor. So ong asthe pressure of the hand remains upon the lever 33, the

switch will be maintained closed and the motor continued in o eration.Upon relieving pressure from t e linger piece 39 of the lever 33, thespring 40 will return the lever 33 to its normal position, whereby thelink or connect/ing rod 36 will be pulled back to its normal position,the toggle will be broken downwardly and the link 26 will be snappedupwardly into its normal full line position, whereby the switch will beopen and the motor will be stopped. Y

The s 'tch may be maintained closed and the motor in operation bythrusting a pin or other device into the openingf 34 in the handle 7 andin rear of the lever 33 so as to maintain the same in its dottedposition.

The same result ma be accomplished, reference being had to igure 4 ofthe drawing, by thrustingl a pin or the like into an opening 49 in t ecasing 50 which incloses the switch, said in overlyin the free endportion of the link 26 and olding it down in en a ment with the contacts19.

enever it is desired to remove the handle or to have access tothe motor,the pivotal connection 38 is removed through the opening 34 in thehandle, andthe fastenings 4 are removed from the head 3, whereupon thelatter, the handle and the mechamsm contained therein, with theexception of the link or rod 36, may be withdrawn from the cas' and theswitch .without in any mannerl'xdgisturbing 'the latter electricalconnections. A

' casing and or any of the.-

` v through the slot in the handle, a spring to l front of and alsoindependent of the handle 7 theseveral parts of the tool may beassembled, and prior to fitting the handle i BB1/mounting the -switch onthe casing 1 i 1n in glace, the motor and switch may be tested,

ing, a tool spindle projecting at one end of the casing, a removablehandle for the casing, an electric switch for starting and stoping themotor and mounted upon the motor casing, and located in front of thehandle, and a hand-operated switch-actuating means carried by theremovable handle and detachably associated with the switch.

2. An electric tool comprising a motor casing, a tool spindle rojectinat one end of the casing, a remova le hand e for the opposite end ofthecasing, a lswitch for starting and stopping the motor and carried bythe casing vand in front of the handle, a hand-operated lever fulcrumedupon 'the handle, and a detachable operatin connection between the leverand the switc 3. An electric tool comprising a motor casing, a toolspindle projectin at oneend of the casing, aremovable-hea for theopposite end of the casing, a handle carried by the removable head andprovided with a longitudinal slot, a switch forstarting and4 stoppingthe motor and mounted upon the motor casing, a hand' operated leverfulcrumed within the slot portion of the handle, a connecting memberbetween the lever andthe switch, and a detachable pivotal connectionbetween the'connecting member and the lever;

V4. An electric tool comprisingj a motor casing', a tool spindleprojectin at oneend of the casing, a removable headr for the oppositeend of the casing, a switchfor starting and stopping the motor andmounted on the casingand located in front of the handle, a-handle 0f thehand-saw type carried by the removable head, a lever fulcrumed upon thevhandle and having a finger portion lying between the handle and theremovable head, and a detachabley connection between the lever and theswitch.

5, An electric tool comprising a motor casing, a tool spindle projectinat one end of the casing, a removable hea for the oposite end of thecasing, a handle of the and-saw type carried by the removable head, theip portion of the handle bein hollow an provided with a longitudina slotin its' front face, a switch forv starting and stoppin themotorandmounted on the located in front of the handle, a lever fulcrumedvwithin thewhandle and having a nger portion extending outwardlyieldably maintainjthe finger portion of the ever in its forwardposition, and a link detachably connecting the other .end of the leverwith the switch.

'6. An electric tool comprising a motor casing, a tool spindleprojecting at one end of the casing, a handle at the opposite end of thecasing, a switch for starting and stopping the motor and mounted on thecasing, and hand-operated means for actuating the switch and including alever having a portion ulcrumed within the handle, said handle havinglan opening adjacent the lever for the reception'or` a pin or plug tohold the lever in the closed condition of the switch.

7. An electric tool comprising a motor casing, a tool spindle projectingat one end of the casing, aremovable head for the op posite end of thecasing, a handle of the hand-saw type carried by the head, the gripportion of the handle being hollow and provided with a longitudinal slotin its front side, a switch for starting and stopping the motor andcarried by the motor casing, means for manually operating the switchincluding a lever fulcrumed intermediate of its ends within the hollowportion of the handle and provided with the finger portion lying betweenthehan'dle and the removable head, a spring for yieldably maintainingthe inger portion of the lever at its forward limit, a link extendingthrough a bore in the handle and having. one end pivotallv connected toa movable part of the switch, and

a screw threaded pivot pin detachably oonnecting the linkto the lever,the handle being provided with an opening to give access to theremovable pivot connection.

8. An electric tool comprising a motor casing, a tool spindle, a handleon the casing, a switch for starting and stopping the motor and mountedon the casing, a hand operated means for actuating the switch andincluding a lever having a portion fulcrumed `within the handle, andsaid handle having an opening adjacent the lever for tool spindleprojecting at one end of the' casing, a removable handle for theopposite end o f the casing, a Switch for starting and stopping themotor and carried by the casing and in front of the handle, a hand-Y yoperated lever Jfulcrumed upon the handle, and a detachable operatingconnection between the lever and the switch.

CHARLES B. BENNETT.

